Evaluating White Grub Control

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Now is the time to plan your preventative white grub programs to maximize control. Here’s how:

  • Timing is everything – Start applications when you see the first adult beetles (usually early-July to mid-August). Merit® has a long soil residual under “typical” conditions, but weather extremes may shorten this period.

  • Apply the right rate - Regardless of formulation, it is critical the full label rate of imidacloprid (0.4 lbs ai/A per year) be applied (period). Be careful with some combination Merit/fertilizer products because their high label rate equates to less than 0.4 lbs ai/A. Here are the proper rates:
    • Merit 75WSP = 5 x 1.6 oz packet/A per year
    • Merit 0.5 G = 80 lbs/A per year
    • Merit 2F = 1.6 pt/A per year
    • 0.2% Merit on Fert = 200 lbs/A per year

  • Water it in - Irrigation or rainfall (≥ 0.5 inch) should occur within 24 hours after application to move the active ingredient through the thatch into the soil profile
  • Minimize thatch - Thatch layers > 0.5 inch can severely limit insecticide movement to the area of grub feeding
  • Exciting New Chemistry from Bayer - Tetraniliprole™ (coming soon) – A new active ingredient from Bayer has shown effective control of all white grub species in research trials conducted over the past several years with key university cooperators. Tetraniliprole has also shown excellent control of other important pests like annual bluegrass weevil, caterpillars, and chinch bugs. Stay tuned for more information on this exciting new solution.  Tetraniliprole is not yet registered and not yet for sale
  • Need more info? - See linked Bayer Solutions Guide and Green Solutions Update for more information, and contact your Bayer area sales manager if you need assistance

White grub control is largely weather dependent, so optimizing management strategy is critical. (Zac Reicher, Bayer).

  Best Management Practices for Effective White Grub Control 
  Bayer Solutions - White Grub - Cool Season Turf 
Rob Golembiewski

by Rob Golembiewski , Ph.D., Green Solutions Team Specialist

Monday, April 13, 2020